95 C280, trouble codes

[shawncisco]

My check engine light came on last week and I had the trouble codes pulled and they gave me 3 codes.
P0301- cylinder 1 misfire
P0300- random cylinder misfire
P0400- (I think) EGR flow malfunction
I'm not positive but when I changed the oil last time I had a vacume line come off from somewhere. And I couldn't find where it came from. But after seeing the EGR code I think that it may have came off the EGR valve or a sensor that attaches to it.
My question is, could a vacume line cause this trouble code?

As for the first 2 codes, I thought I should start at cylinder #1 and replace the plugs, and check the wires and if that didn't fix the problem I would see if I could get the coil tested.
Can anyone tell me if I'm on the right track or if I should be going in another direction.
Thanks

[manny]

Start with a set of sparkplugs and these:
http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1XC0ZKQX926C15SG0A&year=1995&make=MB&model=C-280-001&category=F&part=Spark+Plug+Connector
You could well be right about the egrflow, if the vacuumsource to it is not connected.
May have to have a look at a vacuum diagram, to see where the line is upposed to connect to.

[Arthur Dalton]

Most likely vac line disconnect is the one that goes under the front cover in front of the engine..you have to remove the plastic cover. That line goes to the EGR Switch-Over valve and is a plastic line....they crack from heat fatique and should be rep[aced with a rubber line.
The plug connectors you want to change are the ones under the 3 coils, not the 1st and 3rd in the pic shown. The 2nd one .

This one is the common misfire culprit on all 104 engines.

http://catalog.worldpac.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=21H0MN3YU26C16TZ6M&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1995&product=F1010-84561&application=000357354

If you change plugs , use ONLY Bosch F8DC4/standard copper core..
NO PLATS !!!!

http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=21H0MN3YU26C170AWJ&year=1995&make=MB&model=C-280-001&category=F&part=Spark+Plug